The present invention relates to a safety device, such as a belt roll-up mechanism, a safety belt buckle, and the like, in conjunction with a tensioning mechanism or a force-limiting means of a safety belt system in motor vehicles; a signal device is included for indicating actuation of the tensioning mechanism.
Safety devices such as belt roll-up mechanisms and safety belt buckles are these days frequently combined with tensioning mechanisms; see, for example, U.S. Pat. No. 4,618,108 for a safety belt roll-up mechanism, and DE-OS 39 25 570 for a safety belt buckle.
The fundamental problem with such safety devices is that the pertaining tensioning mechanisms can be actuated unnoticed, with this unintended actuation not being recognizable for the user. Such an unintended actuation can even take place during transport or during assembly of the safety belt system in the motor vehicle, for example in the case of an unused passenger safety belt, without this being recognized. With safety belt roll-up mechanisms it is furthermore desired that the roll-up mechanism still be functionable after actuation of the tensioning mechanism, so that also for this reason the actuation of the tensioning mechanism cannot be recognized by the functioning of the safety belt roll-up mechanism.
To resolve this problem it is already known by use to provide, for example, safety belt buckles having associated tensioning mechanisms with an optical indicator for the effected buckle movement, whereby, for example upon actuation of the tensioning mechanism, a little flag or the like that is recognizable by the user can be released from the housing. In another design, the function of an electrically ignited pyrotechnical rotational tensioner is tested by a diagnosis plug upon maintenance of the vehicle to check for satisfactory functioning and hence for an actuation that may have occurred.
To the extent that mechanically triggered tensioning devices for safety belt systems having mechanical and also pyrotechnical energy actuators are used, such possibilities are not possible for indicating actuation, and frequently the space is also not available for providing optical indicators.
It is therefore an object of the present invention to improve safety devices of the aforementioned general type such that a simple, space-saving actuation indicator can be provided.